I believe changes to a function's return type and argument list should be supported. The caller of such a function would need to have been modified, so if the

I believe changes to a function's return type and argument list should be supported. The caller of such a function would need to have been modified, so if the caller is also not "active" (on the callstack), then the update should be typesafe. They do have limited support for type changes to data - e.g., adding a field to a struct. These must be performed using a "shadow data structure" which holds fields that were added to the original structure. This would cause patches to diverge a bit from the original kernel versions. However, since Ksplice aims primarily to support security patches, I suspect that both function signature and type changes are less common than they would be for general OS (or application) evolution.